There are tens of thousands of pieces of space debris currently orbiting the Earth which pose a potential hazard to satellites, the International Space Station and other space hardware. Since the early 1960s, the existing Air Force Space Surveillance System, also known as the VHF or Space Fence, has been used to track orbital objects passing over America. Proposals are now being taken for the next phase of a new Space Fence that will better detect, report and track orbiting space junk as well as commercial and military satellites.

Last year, the Electronic Systems Center (ESC) – the U.S. Air Force’s organization for developing and acquiring Command and Control systems – awarded three US$30 million contracts to Lockheed Martin, Northrop Grumman and Raytheon to develop a new Space Fence that is scheduled to commence initial operational capability in 2015.

Unlike the current Space Fence’s multistatic radar system, which consists of three transmitter and six receiver sites spread out across the continental U.S. at roughly the 33rd parallel north, the new Space Fence will use multiple globally positioned S-band ground-based radars (Australia is a candidate for the first radar location). The S-band radars will allow for the detection of much smaller microsatellites and debris than the current system thanks to their geographic separation and higher wave frequency. They will also be capable of interoperability with the existing system to ensure there is no gap in capability in the switchover period.

Additionally, the new system will be able to detect space debris that may present potential threats to GPS satellites or the International Space Station more quickly.

“The 2009 collision of an operational communications satellite with a defunct satellite illustrates the real risk space debris poses to both our manned and unmanned space missions,” said John Morse, director of Lockheed Martin’s Space Fence program. “Space situational awareness is a national security priority and Space Fence will greatly enhance our ability to track and catalog orbiting objects which number in the tens of thousands.”

The Space Fence program has now entered its next phase, which will see the ESC award up to two preliminary design review contracts worth up to a total of US$214 million. Over an 18-month period, the selected contractors will develop preliminary system designs, radar performance analyses, evaluations and prototypes, and conduct other technical activities. After completion of this phase in 2012, a separate production contract award is expected to lead to final system development, fielding and full operational capability.